I'm not sure if this helps or not but in my last GP visit my doctor talked with me and could see I was in distress with my symptoms and began telling me that most tests on PCS aren't effective and he reassured me that I really was ill.

He said: When a figure skater gets scared before getting on the ice she
gets nauseous and throws up. Will there be a test to prove
she's sick? No. We have to believe she is because she is.

He also had a story of IBS which I'm also a sufferer of. All tests prove a healthy colon but the patient is still ill because they are.

We're all in this together, it'll be bumpy but we'll get there

Kelly